红外低温相机视轴引出方法

Method to Elicit the Boresight of Infrared Cryogenic Camera

测量红外低温相机的系统调制传递函数(MTF)需要借助于低温平行光管。由于红外低温相机探测器在常温下无法正常工作,并且红外低温相机、低温平行光管离轴抛物镜以及模拟靶标三者是空间分离的,因此实验前需要将相机的视轴引出到平行光管的视轴方向,同时将模拟靶标调整到平行光管焦面位置且靶标中心处于平行光管的中心视场。借助于干涉仪,利用经纬仪分别将相机视轴和平行光管视轴引出到外基准立方镜a和b,通过两立方镜坐标系的方向余弦矩阵关系,将红外低温相机的视轴引出到低温平行光管的视轴方向。对视轴引出精度进行了分析,给出了实验采集的图像。实验结果表明,系统MTF满足要求,同时表明红外低温相机视轴引出方法合理可行。

A cryogenic collimator is needed to test the modulation transfer function（MTF） of the infrared cryogenic camera.The detector of the infrared low temperature camera cannot work normally at room temperature,besides the camera,the off-axis parabolic mirror and the simulated target are spatially separated.So it is necessary to adjust the boresight direction of the camera with the collimator,meanwhile the simulated target must be set on the focal plane and at the 0′ field of the collimator.By using the interferometer,the boresight of the camera and the collimator can be individually elicited to external reference cubes a and b.Based on the direction cosine matrix of the two cubes′ coordination system,the boresight of the camera can be elicited to the direction of the boresight of the collimator.The accuracy of this method is analyzed,and the image of the experiment is also shown.The experimental result shows that the MTF of the camera meets the demand,and it also indicates that the method is reasonable and feasible.